
9 Medical Oncologic Emergencies You Need to Know
In the above image, a severe case of chemotherapy-induced mucositis resulted in the shedding of the ventral portion of the patient's tongue. Poor oral hygiene and advanced dental caries may have also played a role in this tissue loss.
Medical emergencies in patients with cancer can arise as complications of the disease itself and/or treatment for the tumor(s). It is critical that clinicians across all specialties not only be aware of, and quickly recognize, the potential oncologic emergencies that may occur in these patients, but also know how to provide urgent and effective care to manage such clinical crises.[1,2]
9 Medical Oncologic Emergencies You Need to Know
Tumor Lysis Syndrome
Hematologic cancers, fast-growing and bulky tumors, and neoplasms that are highly responsive to treatment can cause tumor lysis syndrome (TLS), a constellation of severe metabolic disturbances, after the initiation of chemotherapy or radiation; it usually occurs within 72 hours of treatment.[1,2]
As tumor cells die and their cell walls break down (shown), they release potassium, phosphorus, proteins, and nucleic acids. The nucleic acids further break down into uric acid.
Hyperphosphatemia caused by TLS can result in hypocalcemia, tetany, seizures, and cardiac dysrhythmias.[3]
Hyperuricemia can lead to renal failure, which can compound TLS-associated hyperkalemia; this, in turn, can cause cardiac dysrhythmias and death.[4]
9 Medical Oncologic Emergencies You Need to Know
Prevention of TLS is the best way to reduce mortality from this condition; however, if TLS develops, treatment should include aggressive fluid hydration. Diuretics may be used to increase urine output and potassium excretion, and rasburicase, a DNA recombinant urate oxidase enzyme, may be administered to reduce the serum concentration of uric acid.
If hyperkalemia is suspected, the patient should remain on cardiac monitoring and an ECG should be obtained. Calcium should be administered to prevent dysrhythmias. In severe cases, patients may require dialysis.[4]
9 Medical Oncologic Emergencies You Need to Know
Hypercalcemia of Malignancy
The most common cause of hypercalcemia of malignancy is the secretion of parathyroid hormone (PTH)–related protein by the tumor; this protein mimics PTH and leads to bone resorption and decreased renal calcium excretion. Symptoms/signs of hypercalcemia of malignancy can include nausea, lethargy, and confusion.[4]
Clinicians should calculate the patient's ionized serum calcium level to accurately assess the severity of hypercalcemia. Intravenous (IV) hydration is the initial treatment for hypercalcemia, and IV bisphosphonates are the next line of therapy. Review the patient's medication list: Some drugs (eg, thiazide diuretics) can increase calcium resorption. Dialysis may be required if the patient cannot tolerate large volumes of IV hydration.[4]
9 Medical Oncologic Emergencies You Need to Know
Neutropenic Fever
Neutropenic fever, or febrile neutropenia, can be defined as a condition in which a patient with an absolute neutrophil count (ANC) of less than 500 cells/µL (or whose ANC is <1000 cells/µL and is expected to drop to <500 cells/µL in the next 48 hours) has an oral temperature above 38°C (100.4°F) for longer than 1 hour or a single oral temperature of at least 38.3°C (100.9 °F).[5] Patients on cytotoxic chemotherapies and those with hematologic cancers are at highest risk for this condition. The risk for infection is also increased by the presence of indwelling ports. Early IV antimicrobial treatment reduces mortality in patients with neutropenic fever. Antibiotics should never be delayed for blood or culture draws.
9 Medical Oncologic Emergencies You Need to Know
Typhlitis
Typhlitis, also known as neutropenic enterocolitis, starts with inflammation of the ileocecum and progresses to necrosis. It is most commonly seen in patients with leukemia or lymphoma. Mortality in untreated individuals approaches 100%. Patients may present to the emergency department with fever, diarrhea, melena, and abdominal pain.[6] Severe neutropenia predisposes patients to this life-threatening condition.
A computed tomography (CT) scan, the diagnostic test of choice, may show bowel wall thickening (arrows), fat stranding, pneumatosis intestinalis, or ileus. Treatment includes administration of IV fluids and broad-spectrum antibiotics, as well as bowel rest. If bowel wall perforation, severe sepsis, or clinical worsening occurs despite appropriate treatment, obtain emergent surgical consultation.[7]
9 Medical Oncologic Emergencies You Need to Know
Hyperviscosity Syndrome
The above CT scan demonstrates bowel ischemia, one cause of which is hyperviscosity syndrome; the small bowel has acquired dilated loops and thickened walls (arrow).
Hyperviscosity syndrome occurs when elevated gamma globulins in the bloodstream increase the viscosity of circulating blood.[8] Patients with Waldenström macroglobulinemia or multiple myeloma are most commonly affected.[2]
Mucocutaneous bleeding, such as epistaxis; neurologic symptoms, including seizure, stroke, and coma; and visual changes make up the classic triad.[2] Bowel ischemia may develop, and heart failure can occur due to the expansion of circulating plasma volume.[8] The initial diagnosis should be made clinically. A complete blood count with peripheral smear may show rouleaux formations, and a serum viscosity test can be ordered. Treatment is emergent plasmapheresis.[9]
9 Medical Oncologic Emergencies You Need to Know
Superior Vena Cava Syndrome
SVC syndrome occurs in patients with cancer when a mass compresses the SVC, causing its partial or complete obstruction and thus compromising the return of blood to the heart. Most cases result from malignancy, specifically lung cancer and lymphoma; however, thrombosis and post-radiation fibrosis are also potential causes.[1,10]
Shortness of breath and facial swelling are the most frequent manifestations among presenting signs and symptoms. Airway compression, laryngeal edema, pleural effusion, and cerebral edema may develop.
9 Medical Oncologic Emergencies You Need to Know
Physical examination findings in patients with SVC syndrome may include facial plethora and neck vein distention. Horner syndrome, which includes a small pupil, drooping eyelid, and anhidrosis, on one side of the face, may be present. Obtaining a chest radiograph is an appropriate first step in making the diagnosis, as most of the images will be abnormal and will show signs of a mass.[10] However, chest CT scanning with contrast is the ideal imaging test (see the image on the previous slide).
As a temporizing measure, an interventional radiologist can place a stent for symptomatic relief. Chemotherapy and radiation therapy are used as definitive treatments, although long-term survival is generally poor.[10]
9 Medical Oncologic Emergencies You Need to Know
Mucositis
Chemotherapy and/or radiotherapy have many painful side effects, including mucositis. In severe cases, patients can develop ulcers that reach the submucosa. Although mucositis most often results from cancer treatment, clinicians should be aware that opportunistic infections can also cause the condition. In addition, mucositis can be the presenting sign of graft-versus-host disease (GvHD). While oral lesions are the easiest to diagnose, mucositis can affect any part of the gastrointestinal (GI) tract.[11]
9 Medical Oncologic Emergencies You Need to Know
Severe mucositis with a confluent pseudomembranous mucosa is shown in a patient undergoing chemotherapy for nasopharyngeal carcinoma.
Symptomatically, mucositis causes severe pain, leading to reduced oral intake. The breakdown of the mucosal barrier (shown) puts patients at high risk for secondary infections and even bacteremia.[11]
Ice chips, saline rinses, topical lidocaine, and topical nystatin have all been used with varying degrees of improvement.[12] IV analgesia is often required for pain control.
9 Medical Oncologic Emergencies You Need to Know
Graft-Versus-Host Disease
A maculopapular rash in a patient with GvHD is shown in the image on the left. The endoscopic image on the right reveals edematous, red, friable GI mucosa in another individual with GvHD.
GvHD occurs when immune cells from transplanted tissue attack the recipient's tissues. This condition most commonly arises after stem cell transplantation, but it also can develop following solid organ transplantation.[13] Acute GvHD is defined as occurring within 100 days of transplant.[13] The skin is most frequently affected and usually presents with a maculopapular rash.
At its worst, GvHD can be similar in appearance to toxic epidermal necrolysis, with bullae, mucous membrane desquamation, and extensive skin involvement. If present, rash involving the palms and soles and GI symptoms (eg, watery diarrhea, hyperbilirubinemia) make the existence of GvHD more likely than that of toxic epidermal necrolysis. GvHD should also be considered in patients with culture-negative fevers.[14]
9 Medical Oncologic Emergencies You Need to Know
The thickened skin of a patient with steroid-refractory cutaneous GvHD is shown. At different periods, treatment was attempted with methylprednisolone, cyclosporine A, tacrolimus, photo sensitizer 8-methoxypsoralen ultraviolet A (PUVA), photopheresis, and thalidomide—all with limited effect.
9 Medical Oncologic Emergencies You Need to Know
Pain
Used for palliative sedation in terminal cancer, the above infusion pump reservoir contains midazolam and morphine.
Many patients with cancer will suffer pain at some point. Acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) should be considered first-line treatments for mild pain in cancer. NSAIDs work synergistically with opioids and can be particularly useful for treating pain from connective tissues, joints, and bones. Hydrocodone, oxycodone, codeine, and tramadol are second-line treatments for mild cancer-related pain.[15]
9 Medical Oncologic Emergencies You Need to Know
Moderate to severe pain in patients with cancer can be treated with morphine, hydromorphone, methadone, or fentanyl. The dosing can be titrated without a ceiling to achieve analgesia. Because morphine is excreted renally, clinicians should use cautious dosing in patients with evidence of reduced creatinine clearance. Hydromorphone is metabolized hepatically and thus may not be appropriate in patients with liver dysfunction.
Methadone has the benefit of a long half-life; however, it can cause significant QT prolongation and subsequent torsade de pointes. Fentanyl is lipophilic and can be absorbed across the skin and mucosa. Although the analgesic effect of fentanyl is equivalent to that of morphine, the side effects of drowsiness and constipation associated with morphine are less common with fentanyl. However, transdermal fentanyl titration can be dangerous due to variable absorption rates and should not be started in the emergency department.[15]
9 Medical Oncologic Emergencies You Need to Know
Adjuvant analgesia
The above image demonstrates spinal cord edema (yellow arrow) resulting from intramedullary metastasis (white arrow) of cholangiocarcinoma.
Some adjuvant analgesics have been studied in patients with cancer, with mixed results.[15] Tricyclic antidepressants for the treatment of neuropathic pain have had varying effects in studies. In elderly patients, the potential benefits of these medications are outweighed by the risks of hypotension, cardiac dysrhythmias, and delirium.
Subdissociative doses of ketamine may improve pain control in hospitalized patients.
Corticosteroids can be effective in the treatment of bone pain from liver metastases. Cerebral or spinal cord edema (above) due to cancer lesions can also improve with steroid administration.
9 Medical Oncologic Emergencies You Need to Know
Gabapentin has shown efficacy in treating neuropathic pain, but the patient's creatinine clearance must be considered prior to administration. Gabapentin must be titrated slowly and can cause altered mental status. IV or subcutaneous lidocaine can also be considered for pain relief, but this agent is not appropriate for patients with cardiac conditions.[15]
Cannabinoids have been used to treat pain that is not well controlled with opioid therapy. Although some studies have shown improvement in pain control with cannabinoid use, such treatment is not considered first line, and it appears to be most useful in combination with other pain medication regimens.[15]
Comments